The application relates to a fastening device for a seat belt.
A conventional fastening device of this type for a seat belt is disclosed in German patent specification DE 197 80 583 C1 (incorporated by reference herein). The conventional fastening device is a belt retractor having a belt-force-limiting element. The belt-force-limiting element is formed in the conventional belt retractor by means of a torsion bar and a torsion sleeve. The manner of operation of the belt retractor is as follows: if a vehicle accident occurs, then the vehicle occupant will “plunge” into the seat belt due to his kinetic energy; this “plunging movement” causes a tensile force to suddenly be exerted on the locking seat belt. If the seat belt were not able to yield, then a considerable restraining force would be built up on the vehicle occupant, as a result of which serious injuries could occur. In order to avoid this, the conventional belt retractor is provided with the torsion bar and the torsion sleeve which, owing to their torsion, cause an unrolling of the seat belt and therefore a lengthening of the seat belt. The further unrolling causes a reduction in the restraining force, and injuries by the belt are avoided.